A pressurized-water coolant reactor installation ordinarily includes the reactor pressure vessel, a steam generator containing a heat exchanger through which the coolant from the vessel is circulated, and a coolant pump which draws or sucks the coolant from the heat exchanger's outlet and discharges it to the pressure vessel via a pipe line which forms a loop with one leg going from the vessel to the steam generator and the other leg, via the coolant pump, returning to the vessel.
The steam generator has a vertical housing with its lower portion closed by a tube sheet in which the inlet and outlet legs of an inverted U-shaped tube bundle heat exchanger are mounted, the housing below this tube sheet being partitioned to form inlet and outlet manifolds for the inlet and outlet ends of the heat exchanger. Ordinarily a pipe from the vessel connects with the inlet manifold and a separate pipe connects the outlet manifold with the pressure vessel via the coolant pump.
To improve on the above, it has been proposed in U.S. Application No. 393,287 filed Aug. 31, 1973 that the coolant pump be built into the housing below the steam generator's tube sheet with the construction providing concentric inlet and outlet coolant connections connected to the pressure vessel by concentric inner and outer pipes. This has the disadvantage that the construction of such a dual pipe line is expensive and complicated, it being necessary to provide supports between the inner and outer tubes to hold them in their concentric position. The supports must be interposed as obstructions to the coolant flow.
The object of the present invention is to provide a construction providing a simpler and less expensive way for dividing the two flows within one pipe.